Directory structure

The top level directory of this repository is the appengine package. It contains the basic APIs (e.g. appengine.NewContext) that apply across APIs. Specific API packages are in subdirectories (e.g. datastore).

There is an internal subdirectory that contains service protocol buffers, plus packages required for connectivity to make API calls. App Engine apps should not directly import any package under internal.

Updating from legacy (import "appengine") packages

If you're currently using the bare appengine packages (that is, not these ones, imported via google.golang.org/appengine), then you can use the aefix tool to help automate an upgrade to these packages.

Run go get google.golang.org/appengine/cmd/aefix to install it.

1. Update import paths

The import paths for App Engine packages are now fully qualified, based at google.golang.org/appengine. You will need to update your code to use import paths starting with that; for instance, code importing appengine/datastore will now need to import google.golang.org/appengine/datastore.

2. Update code using deprecated, removed or modified APIs

Most App Engine services are available with exactly the same API. A few APIs were cleaned up, and there are some differences:

appengine.Context has been replaced with the Context type from golang.org/x/net/context.

Logging methods that were on appengine.Context are now functions in google.golang.org/appengine/log.

appengine.Timeout has been removed. Use context.WithTimeout instead.

appengine.Datacenter now takes a context.Context argument.

datastore.PropertyLoadSaver has been simplified to use slices in place of channels.

delay.Call now returns an error.

search.FieldLoadSaver now handles document metadata.

urlfetch.Transport no longer has a Deadline field; set a deadline on the context.Context instead.

aetest no longer declares its own Context type, and uses the standard one instead.

taskqueue.QueueStats no longer takes a maxTasks argument. That argument has been deprecated and unused for a long time.

appengine.BackendHostname and appengine.BackendInstance were for the deprecated backends feature. Use appengine.ModuleHostnameand appengine.ModuleName instead.